Propane Facts

Frequently Asked Questions About Propane

What is propane? Propane is a hydrocarbon and is sometimes referred to as liquefied petroleum gas, LP-gas or LPG. Propane is produced from both natural gas processing and crude oil refining, in roughly equal amounts from each source. Most propane used in the United States is produced domestically, with about 15 percent imported. It is nontoxic, colorless, and virtually odorless. As with natural gas, an identifying odor is added so the gas can be readily detected. Propane is one of the cleanest burning of all fossil fuels and it fulfills energy needs by efficiently giving consumers more value for their energy dollar.

What is temperature compensation of propane?What It Means to You. Let’s look at the way temperature compensation works so you can understand what is happening. A TC is a device that monitors the temperature of propane going through the metering device. All dealers have temperature compensations (TCs) on their delivery meters. Its purpose is to deliver a constant heating value of fuel to a customer no matter its temperature. Since propane is less dense at higher temperatures, there is less heating value to a gallon of propane in the summer than there is in a gallon of propane in the winter. The TC makes an adjustment to the meter so the customer gets the same heat energy (same number of Btus) in a metered (billed) gallon, no matter when the fuel is delivered. Consider a gallon bucket. Say that I put one gallon of liquid at 60° F in that container, so it is completely full with nothing overflowing. If we cool that gallon by 20-30°, we can see the container isn’t full anymore. Similarly, if we heat it to 80-90°, it will overflow. This example will work with water, but the effect is more pronounced with propane, except that a bucket doesn’t work well with propane. LP gas meter compensation is normalized to 60°. A compensated meter and an uncompensated meter will deliver identical gallons at 60°, assuming everything is working properly. If the temperature gets to 80°, the uncompensated meter will still deliver a gallon but will have fewer Btus of energy. A compensated meter delivers something else (volumetrically) but it will have the same number of Btus as when it was 60°. A few things that are not compensated are; gauges on tanks, be they rotogauges, magnetic level gauges or any other gauges based only on volume. And that’s on all tanks; bulk plants, bobtails, transports, railcars and residential tanks.

Now consider a 250-gallon propane tank that does an impossible thing; it neither expands when heated nor shrinks when cooled. The tank is normally filled to 80%. If you start with an empty tank, you will put 200 gallons into it. If the propane is 60° when you fill it, your meter should read 200. If it is 80°, you still fill it to the same 80% level and there will be 200 actual gallons in it and that’s what an uncompensated meter will read. However, the compensated meter will read something less than 200. It will be more like 193.4, a difference of nearly 7 gallons. Similarly, if it is 30° the tank will still be filled to the 200-gallon level (80%) if you read a gauge on the tank or fill by the bleed valve but the compensated meter will read that 209.4 gallons were delivered. That’s a swing of 16 gallons over 50°.

That’s how that numbers work. This article is not the place to try to explain how to do the numbers. However, if you want to explore for yourself, look at the LP Gas Code, Annex F, Liquid Volume Tables, Computations and Graphs. The numbers I calculated came from using Table F.3.3, Liquid Volume Correction Factors.

So, if everything is adjusted for temperature, why does it seem gas is being lost? Easy. Not everything is really being adjusted for temperature. NIST Handbook 44 requires TC only for delivery to consumers. First, let’s discuss what is adjusted. Propane coming from most pipelines and terminals is metered through temperature compensated meters. Propane coming from many rail terminals is “compensated” because the terminal determines the amount of the load by weighing it. A gallon equivalent of propane weighs the same amount whether it is a light “large” gallon at a higher temperature or a dense, “small” gallon at a lower temperature. Note that a truckload will be lighter in the summer and heavier in the winter if it is filled to the same level both times.

Who uses propane? Propane is used by millions of Americans each day. People use propane in and around their homes for furnaces, water heaters, air conditioners, outdoor grills, fireplaces, and appliances; on farms for pest control, crop drying, and irrigation pumps; for industrial uses such as forklifts and fleet vehicles; and in millions of commercial establishments, including restaurants and hotels, for heating, cooking, and other uses.

Is propane safe to use in my home? Yes. Propane has a narrow range of flammability and cannot be ingested like gasoline or alcohol fuels because it is released as a vapor from a pressurized container. Paul Tuemler LP Gas performs a LeakTest to ensure that homeowners understand how to properly maintain their propane appliances and enjoy a healthy, safe environment.

Crude Oil and Natural Gas Prices - Because propane is derived from both crude oil and natural gas, its price tracks the prices of those energy sources, particularly the cost of crude oil, since propane competes mostly with crude-oil based fuels for heating.

Seasonal Weather Conditions - Colder temperatures during the winter months increase the demand for propane, particularly for home heating. This, in turn, reduces supplies and leads to higher prices. Propane retailers are prepared to meet the demand but predictions of long-term weather trends are difficult.

International Influences - The global propane market is constantly changing. New customers all over the world are turning to propane as a home energy source. As a result there is increased competition for propane.